1. Field of the Invention
This invention relates to structures for supporting insulation in metal buildings, and, more particularly, to structural elements extending between purlins for supporting insulation between the purlins in metal building structures.
2. Description of the Prior Art
U.S. Pat. No. 1,574,329 (White) discloses cross bracing for structural members between "C" type purlins. The cross braces extend generally diagonally from the top of one purlin to the bottom of an adjacent purlin. They accordingly define an "X" configuration between purlins. Each cross brace consists essentially of three portions, a central strap portion and two end portions riveted to the central strap. The end portions are configured to be secured to the flanges of the purlins. The end members may be considered as clips to be fastened onto the flanges. The flanges are referred to in the patent as eye-beam structural members with marginal flanges which extend respectively downwardly and upwardly from the outer end of the top and bottom horizontal flanges.
U.S. Pat. No. 4,147,003 (Alderman) discloses a roof structure for a steel building. The structure includes a support grid between purlins and insulation material disposed on the structural grid. The structural grid is not claimed in detail. The apparatus is designed primarily for "Z" shaped purlins. The structural grid, in each case, is secured to the top flange of each purlin.
U.S. Pat. No. 4,251,972 (Interlante) discloses a structural support member usable with "Z" shaped purlins for supporting insulation between the purlins. The structural support member has a center configuration between purlins of a generally flat "U" shape, with the arms extending slightly outwardly from a relatively wide center web portion. One end of the support member is plain, and is disposed on the top of a bottom flange of one purlin. The opposite end of the support member is curved to fit underneath an adjacent purlin and to hook onto the bottom flange of the adjacent purlin.
U.S. Pat. No. 4,263,763 (Bouwens) discloses an insulation support structure for metal buildings, with the structure extending between bottom flanges of "Z" type purlins. The support members extend longitudinally, and a panel extends between the support members. The insulation is in turn disposed on the panel. The support members accordingly are lengthwise with respect to the purlins, with the panels extending corsswise between the purlins.
U.S. Pat. No. 4,266,384 (Orals et al) discloses a ceiling furring system for supporting insulation. Channels to which gypsum board ceiling panels are secured are fastened to ceiling joists by means of furring clips. Insulation is then disposed on top of the gypsum board ceiling panels and the channels. The cross sectinal configuration of the channels is that of a generally wide "U" with the arm of the "U" disposed slightly outwardly. Flanges extend outwardly from the tops of the arms. The flanges are generally parallel to the bottom of the channel.
U.S. Pat. No. 4,303,713 (Clemensen et al) discloses a roof insulation system in which a medium density thermo-insulation blanket extends between "Z" configured purlins, and low density insulation is disposed on top of the medium density insulation. The medium density insulation is generally self supporting between adjacent purlins. The self supporting medium density insulation is disposed or supported on the top elements of adjacent purlins and on top of longitudinally extending metal bands. The bands extend parallel to the purlins, and transversely or laterally extending bands are in turn secured to the longitudinally extending bands. The transverse or lateral bands are disposed on the purlins.
U.S. Pat. No. 4,375,741 (Paliwoda) discloses a method and apparatus for installing insulation in metal buildings, including a grid support extending between purlins. The grid includes diagonally extending members and support members that are secured to the top flanges of the purlins. Insulation is in turn disposed on the grid structure. The apparatus is designed for the "Z" shaped purlins. The cross-sectional configuration of diagonal members is that of a relatively wide "U" with the arms extending outwardly from the bottom element.
U.S. Pat. No. 4,379,381 (Holcombe) discloses another type of insulation system, including a support structure secured to "Z" shaped purlins and insulation disposed on top of the support structure. The support structure includes rigid structural elements extending between and secured to the purlins, and specifically to the top flanges of the purlins. While the cross members are thus secured to the top flanges of the purlins, there are additional rigid structural support members extending between the cross members and disposed substantially parallel to the purlins. On top of this supporting structure are disposed at least two different kinds of insulation elements, including a bottom semi-rigid layer. The lower, or bottom, semi-rigid layer includes a vapor barrier. Several different embodiments of the insulation layers are illustrated.
U.S. Pat. No. 4,384,437 (Coles) discloses another type of insulation support system for metal building utilizing "Z" type purlins. The insulation system includes a heat insulation sleeve secured to the bottom flange or web of each purlin, and a plurality of cross members extending between purlins for supporting insulation. The cross members are in the general configuration of an inverted "T", and are secured by clips to the purlins. Several different embodiments of the blankets for the purlin webs are shown, with different configurations for different types of purlins. Thus, in addition to the common "Z" type purlin, other types of purlins are also illustrated.
U.S. Pat. No. 4,441,294 (Riley) discloses a support grid for supporting roof insulation in a metal building in which purlins of different cross-sectional configurations are illustrated. The supporting grid includes cross members which are secured to the purlins, and longitudinal members which are in turn secured to the cross members and which extend substantially parallel to the purlins. The cross-sectional configuration of the cross members is generally that of a block "U" with outwardly extending flanges from the ends of the parallel arms of the "U" portions. The cross-sectional configuration of the parallel members, secured to the inverted "U" cross members is generally simply an inverted "U" without the flanges.
Different configurations of cross members are illustrated to extend between purlins of different cross-sectional configurations.